The present invention is concerned with photographic printing systems. In particular, the present invention relates to an improved light source for use in photographic printing systems.
Photographic printers produce color or black and white prints from negatives. High intensity light is passed through a negative and imaged on photographic print paper. A photographic emulsion layer on the print paper is exposed and subsequently processed to produce a print of the scene contained in the negative.
Photographic processing centers typically process film from many customers. The printers used in these processing centers must be capable of producing color and black and white prints from a range of negative sizes which include, for example, 110, 120, 126, 35mm, 70mm and 21/4 .times. 31/4 inches negative sizes. The desired prints may have ten or more different sizes and may be either with or without a border. In addition, some of the orders call for multiple prints from a single negative.
In order to increase efficiency and minimize the time required to fulfill customer orders, high speed printers in which many exposures are made on a single roll of print paper are desirable. After the many exposures are made, the portion of the roll which has been exposed is removed from the printer, is photoprocessed to produce prints, and is cut to individual prints. The prints are then sorted by customer order and ultimately packaged and sent to the customer.
The light source in a photographic printing system plays an important role in determining the overall efficiency of the system. Higher intensity light from the light source allows shorter exposure times and faster operation of the printer.
The typical prior art photographic printer has used a single point source of light for its light source. The light from the point source passes through dichroic filters and is then diffused by a diffuser chamber. Although this type of light source has been generally satisfactory, a light source capable of higher intensity is desirable.